Structural and functional roles of protein components of the cytoskeleton of nonmuscle cells will be analyzed by microinjection experiments. The structural dynamics of alpha-actinin, vinvulin, tubulin and myosin light chain kinase will be followed by time-lapse video recordings made of live cells following microinjection of the various fluorescently labeled proteins. The functional roles of these and other proteins in cell motility will be investigated through the microinjection of antibodies directed against these proteins. The biological consequences of any inhibitory effect of the antibodies on the target antigens will be studied.